ES2595040T3 - Terminal device and corresponding procedure - Google Patents

Abstract

A terminal apparatus comprising: a decoding section (209) configured to decode a downlink control channel, which is transmitted on one or more control channel elements, CCEs, which have consecutive CCE numbers from a base station, in a search space that is composed of a plurality of CCEs that corresponds to a plurality of candidate downlink control channels that are intended for decoding; and a transmission section (220) configured to transmit a response signal to the base station on an uplink control channel, an index of which is associated with a CCE number of the one or more CCEs, in which it is transmitted the downlink control channel, characterized in that: the decoding section is configured to decode the downlink control channel in a search space in which the search space for each aggregation size corresponds to a number of one or more CCEs, in which the downlink control channel is transmitted, and is defined by a number of the plurality of CCEs and an initial CCE number of the search space, the number of the plurality of CCEs and the number of Initial CCE specific for aggregation size.

Description

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TERMINAL DEVICE AND CORRESPONDING PROCEDURE DESCRIPTION

Field of the Invention

The present invention relates to a mobile radio communication station apparatus and response signal procedure.

Background Description

In mobile communications, the ARQ (automatic repetition request) is applied to the downlink data from a radio station base station (hereinafter abbreviated as "base station") to mobile station communication devices by radio (hereinafter abbreviated as "mobile stations"). That is, the mobile stations return response signals representing the results of error detection of the downlink data, to the base station. The mobile stations perform a CRC detection (dclic redundancy check) of the downlink data, and, if it is determined that CRC = OK (i.e. no error detected), an ACK (acknowledgment of receipt) is returned , and, if it is determined that CRC = NG (ie, an error has been detected), a NACK (negative acknowledgment of receipt) is returned, as a response signal to the base station. These response signals are transmitted to the base station using uplink control channels such as PUCCHs (physical uplink control channels).

In addition, the base station transmits control information to notify the results of resource allocation for downlink data and uplink data, to mobile stations. This control information is transmitted to mobile stations using downlink control channels such as PDCCHs (physical downlink control channels). Each PDCCH occupies one or a plurality of CCEs (control channel elements). The base station generates PDCCHs for each mobile station, allocates CCEs for occupancy by the PDCCHs according to the number of CCEs required for the control information, maps the control information with the physical resources associated with the assigned CCEs, and transmits the results.

For example, in order to satisfy the desired received quality, it is necessary to establish a low-level MCS (modulation and coding scheme) for a mobile station that is near the boundary of a cell where the channel quality is poor. Therefore, the base station transmits a PDCCH that occupies a greater number of CCEs (for example, eight CCEs). On the contrary, even if the high MCS level MSC is established for a mobile station near the center of a cell where the channel quality is good, it is possible to satisfy the desired received quality. Therefore, the base station transmits a PDCCH that occupies a smaller number of CCEs (for example, a CCE). In this document, the number of CCEs occupied by a PDCCH is called "CCE aggregation size."

In addition, a base station assigns a plurality of mobile stations to a subframe and therefore transmits a plurality of PDCCHs at the same time. In this case, the base station transmits control information that includes CRC bits encoded by the ID numbers of the destination mobile station, so that the destination mobile station of each PDCCH can be identified. In addition, the mobile stations decode the CCEs with which the PDCCHs can be mapped, and perform the CRC detection after decoding the CRC bits by the mobile station ID numbers of those mobile stations. In this way, the mobile stations detect the PDCCHs for those mobile stations by blindly decoding a plurality of PDCCHs included in a received signal.

However, if there is a greater total number of CCEs, there is an increase in the number of times a mobile station blindly decodes. Therefore, in order to reduce the number of times a mobile station performs blind decoding, a limitation procedure has been studied for each mobile station of the CCEs that are selected for blind decoding (see Document 1, which is not a patent document). With this procedure, a plurality of mobile stations are grouped and the fields of the CCEs selected for blind decoding are limited for each group. Thus, the mobile station of each group needs to blindly decode only the CCE field assigned to that mobile station, so it is possible to reduce the number of times blind decoding is performed. In this document, the CCE field selected to perform blind decoding by a mobile station is called "search space."

In addition, in order to use the downlink communication resources efficiently without signaling to notify the PUCCHs for the transmission of the response signals, from the base station to the mobile stations to transmit the response signals, studies are being conducted to associate CCEs and PUCCHs under a one-to-one relationship (see Document 2, which is not a patent document). According to this association, each mobile station may decide the PUCCH that it will use to transmit a response signal from that mobile station, from the CCE associated with the physical resource with which the information on the map is mapped.

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control for that mobile station. Therefore, each mobile station maps a response signal from that mobile station with a physical resource, based on the CCE associated with the physical resource with which the control information for that mobile station is mapped.

Document 1 (non-patent): 3GPP meeting document RAN WG1, R1-073996, "Search Space definition: Reduced PDCCH blind detection for Split PDCCH search space", Motorola

Document 2 (non-patent): 3GPP meeting document RAN WG1, R1-073620, "Clarification of Implicit Resource Allocation of Uplink ACK / NACK Signal ', Panasonic

3GPP R1-073996 discloses search spaces for aggregation size.

Disclosure of the invention

Problems to be solved by the invention

However, if a plurality of mobile stations are grouped and search spaces are established for each group, a base station needs to notify the search space information indicating the search space of each mobile station, to each mobile station. Therefore, in the prior art, the overhead caused by the notification information increases.

It is therefore an object of the present invention to provide a mobile radio communication station apparatus and a response signal expansion sequence control procedure to reduce the number of times a mobile station performs blind decoding, without increasing overload because of the notification information.

Any occurrence of the term "embodiment" or "embodiment" in the description has to be considered as an "aspect of the invention", the invention being defined in the attached independent claims.

Means to solve the problem

The object is achieved by the subject of the independent claims. Advantageous embodiments are subject to the dependent claims. An example mobile radio communication station apparatus uses a configuration that has: a reception section that receives a first control channel that occupies one or a plurality of control channel elements and that is assigned to a field of element of specific control channel that corresponds to a number of control channel elements occupied by the first control channel, from among a plurality of control channel element fields that are a function of a control format indicator value (CFI ); a decision section that decides a second specific control channel to which a downlink data response signal is assigned from among a plurality of second control channels, based on the control channel element occupied by the first channel of control; and a control section that controls an expansion sequence for the response signal, in accordance with an association that associates the control channel element occupied by the first control channel and an expansion sequence of the second specific control channel and which It is a function of the control format indicator value (CFI).

Advantageous effect of the invention

According to the present invention, it is possible to reduce the number of times a mobile station blindly decodes, without increasing the overhead caused by the notification information.

Brief description of the drawings

Figure 1 is a block diagram showing the configuration of a base station according to an embodiment 1 of the present invention;

Figure 2 is a block diagram showing the configuration of a mobile station according to the embodiment 1 of the present invention;

Figure 3 shows search space information according to the embodiment 1 of the present invention;

Figure 4 shows search spaces according to the embodiment 1 of the present invention;

Figure 5 shows an example of CCE assignment according to the embodiment 1 of the present invention;

Figure 6 shows search space information according to the embodiment 1 of the present invention (in the case where the cell size is large);

Figure 7 shows search spaces according to the embodiment 1 of the present invention (in the case where the cell size is large);

Figure 8 shows search spaces according to an embodiment 2 of the present invention;

Figure 9 shows search spaces according to an embodiment 3 of the present invention (in a

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assignment procedure 1);

Figure 10 shows search spaces according to the embodiment 3 of the present invention (in an assignment procedure 2);

Figure 11 shows search spaces according to an embodiment 4 of the present invention (CFI = 3);

Figure 12 shows search spaces according to the embodiment 4 of the present invention (CFI = 2);

Figure 13 shows search spaces according to the embodiment 4 of the present invention (CFI = 1);

Figure 14 shows the order of priority regarding a use of physical resources associated with PUCCHs according to a

embodiment 5 of the present invention;

Figure 15 shows PUCCH resources according to embodiment 5 of the present invention (CFI = 3);

Figure 16 shows PUCCH resources according to embodiment 5 of the present invention (CFI = 2);

Figure 17 shows PUCCH resources according to embodiment 5 of the present invention (CFI = 1);

Figure 18 shows other search spaces (example 1); Y

Figure 19 shows other search spaces (figure 2).

Best way to make the invention

Next, embodiments of the present invention will be explained in detail with reference to the attached drawings. In the following explanation, the total number of CCEs assigned to a PDCCH is assumed to be 32, from cCe # 0 to CCE # 31, and the CCEs aggregation size of the PDCCH is one of 1, 2, 4 and 8. In addition, if a PDCCH occupies a plurality of CCEs, the CCEs occupied by the PDCCH are consecutive.

In addition, a case will be explained with the following description, in which ZAC sequences (zero auto-correlation sequences) are used in the first PUCCH expansion, and block expansion code sequences, which are used in unit expansion LB (Long Block units), in the second expansion. However, in the first expansion, it is also possible to use sequences that can be separated from each other by different values of cyclic shift, different from the zAc sequences. For example, in the first expansion, it is also possible to use GCL sequences (generalized chirp type sequences), CAZAC sequences (zero constant amplitude auto-correlation sequences), ZC sequences (Zadoff-Chu), or use PN sequences such as M sequences and orthogonal Gold code sequences. Furthermore, in the second expansion, it is possible to use as sequences of block expansion codes, any sequences that can be considered orthogonal sequences or substantially orthogonal sequences. For example, in the second expansion, it is possible to use Walsh sequences or Fourier sequences as sequences of block expansion codes.

Also, in the following explanation, it is assumed that CCE numbers and PUCCH numbers are associated. That is, the PUCCH number is derived from the CCE number used for a PDCCH to use to assign uplink data.

(Embodiment 1)

Figure 1 shows the configuration of a base station 100 in accordance with the present embodiment, and Figure 2 shows the configuration of a mobile station 200 in accordance with the present embodiment.

In this document, to avoid a complicated explanation, Figure 1 shows components associated with the transmission of downlink data and components associated with the reception of uplink response signals to downlink data, which are closely related to the present invention, and the illustration and explanation of the components associated with the reception of uplink data will be omitted. Similarly, Figure 2 shows components associated with the reception of downlink data and components associated with the transmission of uplink response signals to downlink data, which are closely related to the present invention, and omitted. illustration and explanation of the components associated with the uplink data transmission.

In the base station 100 shown in Figure 1, the coding section 101 receives as input search space information indicating the definition of a search space determined by, for example, the cell size and the environment of the Base station. In addition, the encoding section 101 encodes the search space information received as input, and sends the result to the modulation section 102. Next, the modulation section 102 modulates the encoded search space information received as input from the coding section 101 and sends the result to the mapping section 108.

The coding and modulation sections 103-1 to 103-K receive input of resource allocation information for uplink data or downlink data directed to the mobile stations. In this case, each assignment information is assigned to a PDCCH with the CCE aggregation size required to transmit the assignment information. In addition, the coding and modulation sections 103-1 to 103-K are provided in association with a maximum K of mobile stations # 1 to #K. In the coding and modulation sections 103-1 to 103-K, each of the coding sections 11 encodes the information of

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assignment received as input and assigned to PDCCHs, and sends the results to the modulation sections 12. Next, each of the modulation sections 12 modulates the coded assignment information received as input from the coding sections 11, and sends the results to the section of assignment of CCEs 104.

The assignment section of CCEs 104 assigns the assignment information received as input from modulation sections 103-1 to 103-K, to one or a plurality of CCEs based on the search space information. To be more specific, the CCE assignment section 104 assigns a PDCCH to a specific search space associated with the CCE aggregation size of that PDCCH, from among a plurality of search spaces. In addition, the CCE assignment section 104 sends assignment information assigned to CCEs to the mapping section 108. The CCE assignment procedure in the CCE assignment section 104 will be described later.

On the other hand, the coding section 105 encodes the transmission data (ie downlink data) received as input and sends the result to the relay control section 106. In this case, if there is a plurality of elements of transmission. transmission data for a plurality of mobile stations, the coding section 105 encodes each of the plurality of transmission data elements for these mobile stations.

After the initial transmission, the relay control section 106 maintains and sends coded transmission data from each mobile station to the modulation section 107. Next, the relay control section 106 maintains the transmission data until it is received as input one ACK of each mobile station from decision section 117. In addition, if one NACK of each mobile station from decision section 117 is received as input, that is, in retransmission, the relay control section 106 send the transmission data associated with that NACK to modulation section 107.

The modulation section 107 modulates the encoded transmission data received as input from the retransmission control section 106, and sends the result to the mapping section 108.

The mapping section 108 maps the allocation information with downlink allocation resources associated with the assigned CCEs from among the downlink resources reserved for PDCCHs, maps the search space information with downlink resources reserved for channels broadcast and map transmission data with downlink resources reserved for transmission data. In addition, the mapping section 108 sends signals with which those channels are mapped, to the IFFT section (fast reverse Fourier transform) 109.

The IFFT section 109 generates an OFDM symbol by performing an IFFT of a plurality of subcarriers with which the allocation information is mapped, search space information and transmission data, and sends the result to the CP addition section. (Prefix Cfclico) 110.

The addition section of the CP 110 adds as CP the same signal as the signal at the end of the tail of the OFDM symbol, at the head of that OFDM symbol.

The radio transmission section 111 performs the processing of transmissions such as the D / A conversion, the up-conversion amplification and conversion in the OFDM symbol with CP, and transmits the result to the mobile station 200 (of the Figure 2) through antenna 112.

On the other hand, the radio reception section 113 receives an SC-FDMA symbol (multiple access by single carrier frequency division) transmitted by each mobile station, through the antenna 112, and performs reception processing such as the down conversion and the A / D conversion in this SC-FDMA symbol.

The elimination section of the CP 114 removes the CP from the SC-FDMA symbol in which the reception processing is performed.

The reduction section (detaading section) 115 reduces (detaches) the response signal according to the sequence of block expansion codes used in the second expansion in the mobile station 200, and sends the reduced response signal to the processing section of correlation 116.

The correlation processing section 116 determines the correlation value between the reduced response signal and the ZAC sequence that is used in the first expansion in the mobile station 200, and sends the correlation value to the decision section 117.

Decision section 117 detects response signals for each mobile station, by detecting correlation peaks in the detection windows for each mobile station. For example, by detecting the correlation peak in

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Detection window # 0 for mobile station # 0, decision section 117 detects the response signal from mobile station # 0. In addition, decision section 117 decides whether the detected response signal is an ACK or NACK, by synchronization detection using the correlation value of a reference signal, and sends the ACK or NACK to the relay control section 106 for each mobile station.

On the other hand, the mobile station 200 shown in Figure 2 receives search space information, allocation information and downlink data transmitted by the base station 100. The procedures for receiving these information elements are explained below.

In the mobile station 200 shown in Figure 2, the radio reception section 202 receives an OFDM symbol transmitted by the base station 100 (of Figure 1), through the antenna 201, and performs reception processing such as the down conversion and the A / D conversion in the OFDM symbol.

The deletion section of the CP 203 removes the CP from the OFDM symbol undergoing reception processing.

The FFT section (Fast Fourier transform) 204 obtains allocation information, downlink data and broadcast information that includes search space information, which are mapped with a plurality of subcarriers, by performing an FFT of the OFDM symbol, and send the result to separation section 205.

Separation section 205 separates broadcast information in advance mapped with resources reserved for broadcast channels, from signals received as input from the FFT 204 section, and sends the broadcast information to the information decoding section. of diffusion 206 and information different from diffusion information to extraction section 207.

The broadcast decoding section 206 decodes the broadcast information received as input from the separation section 205 to obtain search space information, and sends the search space information to the extraction section 207.

It is assumed that the extraction section 207 and the decoding section 209 receive information in advance of the coding rate indicating the coding rate of the allocation information, that is, information indicating the CCE aggregation size of the PDCCH .

In addition, upon receiving the allocation information, the extraction section 207 extracts the allocation information from the plurality of subcarriers according to the size of the CCE aggregation and the search space information received as input, and sends the information of assignment to demodulation section 208.

The demodulation section 208 demodulates the assignment information and sends the result to the decoding section 209.

The decoding section 209 decodes the allocation information according to the CCE aggregation size received as input, and sends the result to decision section 210.

On the other hand, upon receiving the downlink data, the extraction section 207 extracts, from the plurality of subcarriers, the downlink data for the subject mobile station, according to the result of the allocation of resources received as input from decision section 210, and sends the downlink data to demodulation section 212. This downlink data is demodulated in demodulation section 212, is decoded in decoding section 213 and received as input in the section of CRC 214.

The CRC section 214 detects errors of the downlink data decoded using a CRC, generates an ACK in the case of CRC = OK (without error) or a NACK in the case of CRC = NG (with error), as a response signal, and sends the response signal generated to the modulation section 215. In addition, in the case of CRC = OK (without error), the CRC section 214 sends the downlink data decoded as received data.

Decision section 210 makes a blind detection of whether the allocation information received as input from the decoding section 209 is directed or not to the object mobile station. To be more specific, the assignment information received as input from the decoding section 209 is used by decision section 210 to make a blind detection of whether the assignment information is directed or not to the object mobile station. For example, decision section 210 decides that, if it is determined that CRC = OK (that is, no errors are found) as a result of unmasking the CRC bits according to the ID number of the object mobile station, the allocation information is addressed to that mobile station. In addition, decision section 210 sends the allocation information directed to the object mobile station, that is, the result of the downlink data resource allocation for that mobile station, to the extraction section 207.

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In addition, decision section 210 decides which PUCCH to use to transmit a response signal by the object mobile station, from the number of CCE associated with a sub-carrier with which a PDCCH is mapped, with the allocation information being addressed to that mobile station assigned to that PDCCH. In addition, decision section 210 sends the result of the decision (ie, the number of PUCCH) to control section 209. For example, if a CCE associated with a sub-carrier with which the PDCCH is mapped is directed to the mobile station is the CCE # 0, the decision section 2l0 decides that the PUCCH # 0 associated with the CCE # 0 is the PUCCH for that mobile station. In addition, for example, if the CCEs associated with sub-carriers with which the PDCCH directed to the mobile station is mapped are the CCEs from # 0 to # 3, decision section 2l0 decides that the PUCCH # 0 associated with the CCE # 0 with the lowest number of CCEs among the CCEs from # 0 to # 3, is the PUCCH for that mobile station.

Based on the number of PUCCH received as input from the decision section 210, the control section 211 controls the value of the displacement of the ZAC sequence used in the first expansion in the expansion section 216 and the sequence of expansion codes in blocks used in the second expansion in the expansion section 219. For example, the control section 211 selects the sequence ZAC that has the value of displacement associated with the number of PUCCH received as input from the decision section 210, out of twelve ZAC sequences from ZAC # 0 to ZAC # 11, and establish the ZAC sequence in expansion section 216, and select the sequence of block expansion codes associated with the number of PUCCH received as input from the decision section 210, from among three sequences of block expansion codes from BW # 0 to BW # 2, and establishes the sequence of block expansion codes in section d and expansion 219. That is, control section 211 selects one of the plurality of resources defined by the ZAC sequences from # 0 to # 11 and by the BW sequences from # 0 to # 2.

The modulation section 215 modulates the response signal received as input from the CRC section 214 and sends the result to the expansion section 216.

The expansion section 216 performs the first expansion of the response signal by means of the sequence ZAC established in the control section 211, and sends the response signal subjected to the first expansion to the IFFT section 217. That is, the section of expansion 216 performs the first expansion of the response signal using the ZAC sequence that has the value of displacement associated with the resource selected in control section 211.

The IFFT section 217 performs an IFFT of the response signal submitted to the first expansion, and sends the response signal submitted to an IFFT to the addition section of CP 218.

The addition section of CP 218 adds as CP the same signal as the signal of the final part of the tail of the response signal submitted to an IFFT, at the head of that response signal.

The expansion section 219 performs the second expansion of the response signal with CP by the sequence of block expansion codes established in the control section 211, and sends the response signal submitted to the second expansion to the transmission section by radius 220.

The radio transmission section 220 performs the transmission processing such as the D / A conversion, the amplification and the up conversion of the response signal subjected to the second expansion, and transmits the result to the base station 100 (of the Figure 1) through antenna 201.

Next, the procedure for assigning CCEs in the section for assigning CCEs 104 will be explained in detail.

The allocation section of CCEs 104 assigns the PDCCHs directed to the mobile stations, to a search space associated with the CCE aggregation size of those PDCCHs to which the allocation information is assigned for those mobile stations, from among a plurality of search spaces.

As shown in Figure 3, the assignment section of CCEs 104 receives as input search space information that defines the CCE numbers that represent the initial locations of the search spaces and the numbers of CCEs that represent the lengths of space of search, for each size of aggregation of CCEs. For example, the search space associated with an aggregate size of CCEs equal to 1 is defined when the number of CCEs representing the initial location is CCE # 0 and the number of CCEs is 10. Similarly, the space of search associated with a CCEs aggregation size equal to 2 is defined when the number of CCEs representing the initial location is CCE # 4 and the number of CCEs is 12. The same applies to the case in which the CCEs aggregation size It is equal to 4 or 8.

Therefore, as shown in Figure 4, a search space consisting of ten CCEs from CCE # 0 to CCE # 9 is defined when the CCEs aggregation size is 1, a search space consisting of twelve is defined

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CCEs of CCE # 4 to CCE # 15 when the CCEs aggregation size is 2, a search space consisting of sixteen CCEs from CCE # 8 to CCE # 23 is defined when the CCEs aggregation size is 3, and defined a search space formed by sixteen CCEs from CCE # 16 to CCE # 31 when the size of CCEs aggregation is 4.

That is, as shown in Figure 4, the assignment section of CCEs 104 can assign a maximum of ten PDCCHs of an aggregate size of CCEs equal to 1 to the search space of CCE # 0 to CCE # 9. Similarly, the assignment section of CCEs 104 may assign a maximum of six PDCCHs of an aggregate size of CCEs equal to 2 to the search space of CCE # 4 to CCE # 15, may assign a maximum of four PDCCHs of one CCE aggregation size equal to 4 to the search space of CCE # 8 to CCE # 23, and you can assign a maximum of two PDCCHs of a CCE aggregation size equal to 8 to the search space of CCE # 16 to CCE # 31.

For example, a case will be explained in which the CCE allocation section 104 of the base station 100 assigns six PDCCHs of a CCE aggregation size equal to 1, three PDCCHs of a CCE aggregation size equal to 2, three PDCCHs of an aggregate size of CCEs equal to 4 and a PDCCH of an aggregate size of CCEs equal to 8.

First, as shown in Figure 5, the section of assignment of CCEs 104 assigns six PDCCHs (of an aggregate size of CCEs equal to 1) to the CCEs from # 0 to # 5 in the search space (from CCE # 0 to CCE # 9) associated with an aggregate size of CCEs equal to 1 shown in Figure 4. Next, as shown in Figure 5, the assignment section of CCEs 104 assigns three PDCCHs (of one size of aggregation of CCEs equal to 2) to CCEs # 6 and # 7, CCEs # 8 and # 9 and CCEs # 10 and # 11, to which the PDCCHs with an aggregate size of CCEs equal to 1 are not assigned , in the search space (from CCE # 4 to CCE # 15) associated with an aggregate size of CCEs equal to 2 shown in Figure 4. In addition, as shown in Figure 5, the assignment section of CCEs 104 Assign three PDCCHs (of an aggregate size of CCEs equal to 4) to the CCEs from # 12 to # 15, the CCEs from # 16 to # 19 and the CCEs from # 20 to # 23, to which the CCEs are not assigned PDCCHs with tam Year of aggregation of CCEs equal to 1 and 2, in the search space (from CCE # 8 to CCE # 23) associated with a size of aggregation of CCEs equal to 4 shown in Figure 4. Also, as shown in the Figure 5, the section of assignment of CCEs 104 assigns a PDCCH (of a size of aggregation of CCEs equal to 8) to CCEs from # 24 to # 31, to which the PDCCHs of sizes of aggregation of equal CCEs are not assigned to 1, 2 and 4, in the search space (from CCE # 16 to CCE # 31) associated with an aggregate size of CCEs equal to 8 shown in Figure 4.

The mobile station 200 performs the demodulation, decoding and blind detection of the PDCCHs using the definition of the search spaces based on the aggregation sizes of CCEs. By this means, it is possible to reduce the number of times the blind detection is performed in the demodulation section 208, in the decoding section 209 and in the decision section 210 of the mobile station 200 (of Figure 2). To be more specific, if the blind detection is carried out assuming that the size of CCE aggregation is 1, the extraction section 207 sends to the demodulation section 208 only signals associated with the CCEs from # 0 to # 9 among the CCEs from # 0 to # 31 shown in Figure 4. That is, in demodulation section 208, decoding section 209 and decision section 210, when an aggregate size of CCEs is 1, the purpose of detection blindly it is limited to the search space that supports CCEs from # 0 to # 9. Similarly, if blind detection is performed when the size of CCE aggregation is 2, extraction section 207 sends demodulation section 208 only signals associated with CCEs from # 4 to # 15 among CCEs of the # 0 to # 31 shown in Figure 4. The same applies to the case where the CCE aggregation size is assumed to be 4 or 8.

In this way, each mobile station blindly decodes using search spaces associated with CCE aggregation sizes. That is, by defining a search space information per cell, mobile stations can perform decoding blindly unless a base station notifies the search space information to these mobile stations.

Next, in order to reduce the performance degradation of the error rate of the assignment information, the assignment information MCS directed to the mobile stations near a cell edge is adjusted downwards. Therefore, the size of CCEs aggregation of the PDCCH for mobile stations near a cell edge is increased. For example, outside the CCE aggregation sizes equal to 1, 2, 4 and 8, the CCE aggregation size for mobile stations that are near a cell edge is 4 or 8.

In addition, in a cell with a larger cell size, the proportion of mobile stations that require the transmission of allocation information with an MCS set at a low level, that is, increases the proportion of mobile stations, to which they are assigned PDCCHs of a greater size of aggregation of CCEs. In other words, in a cell of a smaller cell size, the proportion of mobile stations that can transmit allocation information with an MCS set to a high level increases, that is, increases the

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proportion of mobile stations, to which PDCCHs of a smaller size of CCE aggregation are assigned.

Therefore, a base station defines search spaces that go between cell sizes. That is, in a larger cell size, a broader search space is defined for a larger CCE aggregation size, and a narrower search space is defined for a smaller CCE aggregation size. Also, in a smaller cell size, a narrower search space is defined for a larger CCE aggregation size, and a larger search space is defined for a smaller CCE aggregation size.

In addition, the CCE assignment section 104 assigns control information to a specific search space from among a plurality of search spaces defined by each cell.

For example, Figure 6 shows an example of search space information in a cell of a cell size larger than a cell in which the search space information shown in Figure 3 is established. To be more specific, the search space associated with an aggregate size of CCEs equal to 1 is defined when the number of CCE representing the initial location is CCE # 0 and the number of CCEs is 6. Similarly, the space is defined of search associated with a CCE aggregation size equal to 2 when the CCE number representing the initial location is CCE # 2 and the number of CCEs is 8. The same applies to the case where the CCE aggregation size is 4 or 8.

That is, as shown in Figure 7, the assignment section of CCEs 104 may assign a maximum of six PDCCHs of an aggregate size of CCEs equal to 1 to the search space of CCE # 0 to CCE # 5. Similarly, the assignment section of CCEs 104 may assign a maximum of four PDCCHs of an aggregate size of CCEs equal to 2 to the search space of CCE # 2 to CCE # 9, may assign a maximum of five PDCCHs of a CCE aggregation size equal to 4 to the search space of CCE # 4 to CCE # 23, and you can assign a maximum of three PDCCHs of a CCE aggregation size equal to 8 to the search space of CCE # 8 to CCE # 31.

If the search spaces shown in Figure 7 are compared to the search spaces shown in Figure 4, in a smaller CCE aggregation size, that is, in a CCE aggregation size equal to 1 (or a size of aggregation of CCEs equal to 2), the number of PDCCHs assigned is reduced from 10 (6) to 6 (4). On the contrary, in a larger CCE aggregation size, that is, in a CCE aggregation size equal to 4 (or a CCE aggregation size equal to 8), the number of assigned PDCCHs increases by 4 (2 ) to 5 (3). That is, in the CCE assignment section 104, the number of PDCCHs of a larger CCE aggregation size increases by a larger cell size, so that it is possible to assign more PDCCHs of a more CCE aggregation size. big. In other words, in the CCE allocation section 104, the number of PDCCHs of a smaller CCE aggregation size increases by a smaller cell size, so that it is possible to assign more PDCCHs of a CCE aggregation size. smaller.

Thus, according to the present embodiment, only the search spaces defined by each cell are the objective of blind decoding in a mobile station, so that it is possible to reduce the number of times the decoding is performed blindly. In addition, mobile stations specify search spaces based on the search space information disseminated by a base station to all mobile stations, so that no new notification information is required for each mobile station. Therefore, according to the present embodiment, it is possible to reduce the number of times the decoding is performed blindly, without increasing the overhead due to notification information.

In addition, in accordance with the present embodiment, the PDCCHs are assigned to a search space associated with the size of CCE aggregation. Thus, in a plurality of CCEs, the size of CCEs aggregation of the PDCCHs for use is limited. Therefore, according to the present embodiment, by means of the association of PUCCHs with only CCEs of the minimum numbers between the CCEs that form the PDCCHs for their use, it is possible to reduce the amount of resources reserved for the PUCCHs.

In addition, a case has been described above with the present embodiment in which the PDCCHs of all CCE aggregation sizes can be transmitted to a certain mobile station. However, with the present invention, it is also possible to determine the size of CCE aggregation for each mobile station. For example, for a mobile station that is near a cell edge, the quality of the channel is poor, and, consequently, the transmission ratio increases with a lower level MCS. Therefore, the size of CCE aggregation in a mobile station that is near a cell edge is limited to 4 or 8. In addition, for a mobile station that is near a cell center, the quality of the channel it is good, and, consequently, increases the transmission ratio with a higher level MCS. Therefore, the size of CCE aggregation of a mobile station near a cell center is limited to 1 or 2. By this means, it is also easier to specify a search space, so that it is possible to reduce even more the number of times a mobile station performs blind decoding.

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In addition, although a case has been described above with the present embodiment in which the definition of search spaces is established in function of the cell size, with the present invention, it is also possible to establish the definition of search spaces in function of, for example, the bias of the distribution of mobile stations in a cell.

(Embodiment 2)

In the search spaces shown in Figure 4 of embodiment 1, if an odd number of PDCCHs of a given CCE aggregation size is used, there may be a CCE that cannot be used as PDCCH of an aggregation size CCEs larger than the given CCE aggregation size.

For example, in the search spaces shown in Figure 4, if five PDCCHs of an aggregate size of CCEs equal to 1 are used, the CCEs from # 0 to # 4 are occupied. In this case, outside of the PDCCHs of an aggregate size of CCEs equal to 2, the PDCCH formed by CCEs # 4 and # 5 cannot be used because CCE # 4 is already being used. That is, CCE # 5 is not used. Similarly, for example, if three PDCCHs of an aggregate size of CCEs equal to 4 are used, the CCEs from # 8 to # 19 are used. In this case, outside the PDCCHs of a size of CCEs equal to 8, the PDCCH formed by the CCEs from # 16 to # 23 cannot be used because the CCEs from # 16 to # 19 are already being used. That is, CCEs from # 20 to # 23 are not used. Therefore, a part of CCEs that form a PDCCH is used by another PDCCH of a different size of CCEs aggregation and, consequently, the efficiency of use of CCEs is poor.

Therefore, according to the present embodiment, the allocation information is assigned to a specific search space formed by CCEs with smaller CCE numbers in a larger CCE aggregation size.

To be more specific, as shown in Figure 8, a search space consisting of sixteen CCEs from CCE # 0 to CCE # 15 is defined when the CCEs aggregation size is 8, a search space consisting of sixteen is defined CCEs of CCE # 8 to CCE # 23 when the aggregation size of CCEs is 4, a search space consisting of twelve CCEs of CCE # 16 to CCE # 27 is defined when the CCEs aggregation size is 2, and defined a search space consisting of ten CCEs from CCE # 22 to CCE # 31 when the size of CCEs aggregation is 1.

Next, a case will be explained in which the CCE allocation section 104 of the base station 100 assigns five PDCCHs of a CCE aggregation size equal to 1, three PDCCHs of a CCE aggregation size equal to 2, two PDCCHs of an aggregate size of CCEs equal to 4 and a PDCCH of an aggregate size of CCEs equal to 8.

First, as shown in Figure 8, the assignment section of CCEs 104 assigns a PDCCH (of an aggregate size of CCEs equal to 8) to the CCEs from # 0 to # 7 in the search space (from CCE # 0 to CCE # 15) associated with a CCE aggregation size equal to 8. Next, as shown in Figure 8, the CCE assignment section 104 assigns two PDCCHs (of an equal CCE aggregation size a 4) to the CCEs from # 8 to # 11 and CCEs from # 12 to # 15, to which a PDCCH of an aggregate size of CCEs equal to 8 is not assigned, in the search space (from CCE # 8 to CCE # 23) associated with a CCE aggregation size equal to 4. In addition, as shown in Figure 8, the CCE assignment section 104 assigns three PDCCHs (of a CCE aggregation size equal to 2) to CCEs # 16 and # 17, CCEs # 18 and # 19 and CCEs # 20 and # 21, to which PDCCHs of aggregation sizes of CCEs equal to 8 and 4 are not assigned, in the search space (of CCE # 16 to CCE # 2 7) associated with a CCE aggregation size equal to 2. In addition, as shown in Figure 8, the CCE assignment section 104 assigns five PDCCHs (of a CCE aggregation size equal to 1) to the CCEs of the # 22 to # 26 in the search space (from CCE # 16 to CCE # 31) associated with an aggregate size of CCEs equal to 1. Also, CCEs different from CCEs used for PDCCHs, that is, CCEs Unused concentrates on CCE numbers (i.e., from CCE # 27 to CCE # 31) near the final part of the queue between CCEs from # 0 to # 31.

That is, in the section of assignment of CCEs 104, if a plurality of PDCCHs of different sizes of aggregation of CCEs are assigned, it is possible to assign a plurality of PDCCHs to a plurality of consecutive CCEs without causing unused CCEs. By this means, in each CCE, the CCEs are used in order from the CCE with the lowest number of CCEs, and, if there are unused CCEs, it is likely that these unused CCEs will concentrate on the numbers of CCEs near the end of The tail.

Therefore, if CCEs with smaller numbers of CCEs are used in order from the PDCCHs with the largest CCE aggregation size, the CCE assignment section 104 may assign PDCCHs of a different CCE aggregation size in order from of the CCE immediately after the CCEs to which the PDCCHs of a larger size of CCE aggregation are assigned. Therefore, unlike the embodiment 1, it is possible to avoid the unavailability of CCEs because the PDCCHs of an aggregate size of

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Different CCEs are already assigned to these CCEs, so it is possible to assign PDCCHs efficiently. In addition, unused CCEs concentrate on the numbers of CCEs near the end of the queue, and, consequently, for example, a base station reduces and transmits the number of CCEs to which PDCCHs are actually assigned (in the example above, the CCEs are reduced to 27) and they are transmitted, so that it is possible to use available resources (in the previous example, five CCEs from # 27 to # 31) efficiently as data resources. In addition, although unused CCEs are located in locations other than the locations of the CCE numbers near the end of the queue, although a base station may reduce the number of CCEs to which PDCCHs are assigned and transmitted, You need a huge amount of control information to notify which are the unused CCEs. However, as in the present embodiment, when unused CCEs concentrate on the numbers of CCEs near the end of the queue, it is only necessary to notify the number of CCEs to be transmitted, so that only requires a small amount of control information.

Thus, according to the present embodiment, the allocation information is assigned to a specific search space formed by CCEs with smaller CCE numbers in a larger CCE aggregation size. In this way, it is possible to assign the PDCCHs in order from the CCE with the lowest number of CCEs without causing unused CCEs, and concentrate the unused CCEs in consecutive CCEs with CCE numbers near the end of the queue. Therefore, according to the present embodiment, it is possible to assign the PDCCHs to the CCEs more efficiently than in the embodiment 1 and use unused CCEs as data resources efficiently.

(Embodiment 3)

A case in which the downlink assignment information and the uplink assignment information share a plurality of CCEs will be explained with the present embodiment.

The procedure for assigning CCEs in this embodiment will be explained.

<Assignment Procedure 1>

With the present embodiment, in a plurality of CCEs that form a specific search space, the downlink assignment information to notify a downlink assignment result is assigned in ascending order from the CCE with the lowest number of CCE , and the uplink assignment information to notify the result of the uplink assignment is assigned in descending order from the CCE with the highest number of CCEs.

This will be explained in detail below. In this case, the same search spaces as those in Figure 8 of embodiment 2 will be used. In addition, the above will be explained focusing on the case in which the size of CCE aggregation is 1.

As shown in Figure 9, in the search space (CCEs from # 22 to # 31) corresponding to an aggregate size of CCEs equal to 1, the CCE assignment section 104 assigns downlink assignment information (from an aggregate size of CCEs equal to 1) in ascending order from CCE # 22, which is the CCE with the lowest number of CCEs. That is, the assignment section of CCEs 104 assigns downlink assignment information in order from CCE # 22 to CCE # 31. On the contrary, as shown in Figure 9, in the search space (CCEs from # 22 to # 31) corresponding to an aggregate size of CCEs equal to 1, the assignment section of CCEs 104 assigns assignment information of uplink (of an aggregation size of CCEs equal to 1) in descending order from CCE # 31, which is the CCE with the highest number of CCEs. That is, the assignment section of CCEs 104 assigns downlink assignment information in order from CCE # 31 to CCE # 22. The same applies to the sizes of aggregation of CCEs equal to 2, 4 and 8.

In CCEs # 22 through # 31 shown in Figure 9, CCE # 22 is used more frequently as PDCCH for downlink assignment information, and CCE # 31 is used more frequently as PDCCH for uplink assignment information. In other words, CCE # 22 is used less frequently as PDCCH for uplink assignment information. That is, in the CCEs from # 22 to # 31 shown in Figure 9, the CCE # 22, which is used less frequently as PDCCH for uplink allocation information, is used as PDCCH for the assignment of downlink, and CCE # 31, which is used less frequently as PDCCH for downlink assignment information, is used as PDCCH for uplink assignment information.

Therefore, with the present allocation procedure, although the downlink assignment information and the uplink assignment information share a plurality of CCEs, it is possible to obtain the same effect as in embodiment 2 and use the plurality of CCEs efficiently between the downlink assignment information and the uplink assignment information.

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In addition, a plurality of downlink assignment information elements or a plurality of uplink assignment information elements are not transmitted to a mobile station. Consequently, when a mobile station decides the downlink assignment information, performing a blind detection in order from the CCE with the lowest number of CCEs and stopping the blind detection of the downlink assignment information at the time when that the PDCCH is determined for that mobile station, it is possible to reduce an average number of times the blind detection is performed, compared to a case in which the uplink assignment information and the downlink assignment information are mapped randomly. Therefore, according to the present embodiment, it is possible to reduce the energy consumption in the mobile stations.

<Assignment Procedure 2>

With this assignment procedure, the assignment information is assigned to a search space that is symmetrically formed with CCEs that have the smallest CCE numbers and with CCEs that have the highest CCE numbers in the case of a larger aggregation size of CCEs.

This will be explained in detail below. As shown in Figure 10, search spaces defined by eight CCEs from CCE # 0 to CCE # 7 and eight CCEs from CCE # 24 to CCE # 31 are defined when the CCEs aggregation size is 8, spaces are defined search formed by eight CCEs of CCE # 4 to CCE # 11 and eight CCEs of CCE # 20 to CCE # 27 when the size of CCEs aggregation is 4, search spaces defined by six CCEs of CCE # 8 to CCE # are defined 13 and six CCEs of CCE # 18 to CCE # 23 when the aggregate size of CCEs is 2, and a search space consisting of eight CCEs of CCE # 12 to CCE # 19 is defined when the aggregate size of CCEs is 1 .

That is, each search space is formed with CCEs symmetrically with reference to the center of CCE # 0 to CCE # 31 (that is, between CCE # 15 and CCE # 16).

In addition, as shown in Figure 10, in the same way as in Assignment Procedure 1, the CCE assignment section 104 assigns downlink assignment information in ascending order from the CCE with the lowest number of CCE in each search space, and assign uplink assignment information in descending order from the cCe with the highest number of CCEs in each search space. That is, in the CCEs from # 0 to # 31 shown in Figure 10, while the search space (from CCE # 0 to CCE # 15) formed by CCEs with lower numbers of CCEs compared to CCEs Centrals is used more frequently as PDCCHs for downlink assignment information, the search space (from CCE # 16 to CCE # 31) formed by CCEs with higher numbers of CCEs relative to central CCEs is used more frequently as PDCCHs for uplink assignment information.

Thus, in accordance with the present assignment procedure, in comparison to the assignment procedure 1, it is possible to assign downlink assignment information and uplink assignment information of different CCE aggregation sizes separately, from so it is possible to carry out planning more easily to optimize the allocation of CCEs for downlink assignment information and CCEs for uplink assignment information.

The procedures for assigning CCEs have been described above.

Thus, according to the present embodiment, although the downlink assignment information and the uplink assignment information share a plurality of CCEs, it is possible to reduce the number of times the decoding is performed blindly without increasing the overload caused by the notification information.

Also, according to the present embodiment, it is possible to obtain the same effect as before by assigning uplink assignment information in ascending order from the CCE with the lowest number of CCE and assigning downlink assignment information in descending order from of the CCE with the highest number of CCEs from among a plurality of CCEs that form a specific search space.

(Embodiment 4)

With the present embodiment, the allocation information is assigned to a specific search space displaced according to the value of the CFI (Control Format Indicator).

The CFI, which is information that indicates the amount of PDCCH resources, is notified by a base station to mobile stations. To be more specific, the value of the CFI (= 3, 2, 1) is associated with the number of OFDM symbols that include assignment information. At this point, while the previous search space information is disseminated semi-statically by the base station to the mobile stations, the IFC is notified

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dynamically by the base station to the mobile stations for each sub-frame. That is, OFDM symbols that include assignment information dynamically go between sub-frames. Consequently, if the definition of the search spaces is determined based on the number of OFDM symbols that include assignment information, that is, based on the total number of CCEs, it is necessary that the base station notify the space information of searching the mobile stations every time the CFI goes, and therefore increases the overhead caused by the notification information.

Therefore, with the present embodiment, the allocation information is assigned to a specific search space displaced according to the value of the CFI.

This will be explained in detail below. At this point, as shown in Figure 11, the search space used in the case of the CFI = 3 is the same as the search space shown in Figure 8 of the embodiment 2. In this case, As shown in Figure 11, the total number of CCEs Ncce (3) = 32 is maintained. In addition, it is assumed that the initial location of the search space is nccE4 (3) = 8 in the case where the aggregation size of CCEs is 4, the initial location of the search space is nccE2 (3) = 16 in the case where the aggregate size of CCEs is 2 and the initial location of the search space is nccE1 (3) = 22 in the case in which the aggregate size of CCEs is 1, and these values are disseminated in advance by a base station to the mobile stations.

The assignment section of CCEs 104 calculates the search space in the CFI = i (i = 1, 2, 3) and changes the definition of the search space based on the following equations.

nccE4 (i) = nccE4 (3) - Ncce (3) + NccE (i) nccE2 (i) = nccE2 (3) - Ncce (3) + NccE (i) nccE1 (i) = nccE1 (3) - Ncce ( 3) + NccE (i)

At this point, if the calculation result is negative, the initial location of that search space is CCE # 0. In the right member of the above equations, the second term and the third term represent the difference between the total number of CCEs in the CFI sub-frame = 3 and the total number of CCEs in the CFI sub-frame = i. That is, the initial location of the search space corresponding to each size of CCE aggregation in the case of CFI = i moves forward by an amount that is the difference of the total number of CCEs with respect to the initial location of the space of corresponding search to each size of aggregation in the case of the CFI = 3.

For example, in the case of the CFI sub-frame = 2, the total number of CCEs Ncce (2) = 24 is maintained, and therefore

both the assignment section of CCEs 104 defines search spaces based on the above equations. For

be more specific, the initial location of the search space corresponding to each size of aggregation of

CCEs are calculated as follows.

nccE4 (2) = nccE4 (3) - Ncce (3) + Ncce (2) = 0

nccE2 (2) = nccE2 (3) - Ncce (3) + Ncce (2) = 8

nccE1 (2) = nccE1 (3) - Ncce (3) + Ncce (2) = 14

Therefore, the allocation section of CCEs 104 defines the search spaces shown in Figure 12. That is, the search space corresponding to each size of CCE aggregation in the case of the CFI = 2 is obtained by moving the CCE numbers in an amount of eight CCEs, which are the difference between the total number of CCEs in the case of the CFI = 3 (Ncce (3) = 32) and the total number of CCEs in the case of the CFI = 2 (Ncce (2) = 24). That is, in the assignment section of CCEs 104, the search spaces are displaced according to the value of the CFI. Similarly, by calculating the number of CCE that corresponds to the initial location of the search space corresponding to each aggregation size in the case of the CFI = 1 (that is, the total number of CCEs Ncce (1) = 14) , the assignment section of CCEs 104 can obtain the search spaces shown in Figure 13. At this point, in Figure 13, in the calculation of the initial locations nccE4 (1) and nccE2 (1) of the search spaces corresponding to the cases of size of aggregation of CCEs equal to 4 and 2, the calculation results are negative, and therefore the initial locations are nccE4 (1) = nccE2 (1) = 0.

In addition, in the same way as in the CCE assignment section 104, decision section 210 (of Figure 2) of mobile station 200 blindly detects only the allocation information assigned to a specific search space displaced according to the value of the CFI notified by the base station 100, to decide whether or not that assignment information is the assignment information directed to that mobile station. That is, although the IFC is in vain, it is possible to determine a common definition of the search spaces between the allocation section of CCEs 104 of the base station 100 and the decision section 210 of the mobile station 200.

Thus, according to the present embodiment, although the value of the CFI varies, mobile stations can change the definition of the search spaces using the definition of the search spaces disseminated by a base station to the mobile stations. In this way, it is possible to form optimal search spaces based on the value of the CFI without increasing the overhead due to more notification information. Therefore, in accordance with the present embodiment, although the IFC is valid, it is possible to obtain the same effect as in the form of

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realization 1.

(Embodiment 5)

With the present embodiment, a case will be explained in which the CCEs and the PUCCHs are associated.

In the association of CCEs and PUCCHs, a mobile station decides that a PUCCH associated with the lowest number of CCEs from one or more of the CCEs that make up the PDCCH with which the allocation information for that mobile station is mapped, is the PUCCH for that mobile station. Therefore, if all CCEs are associated with PUCCHs according to a one-to-one relationship, in the aggregation of the CCEs a PUCCH is detected that is not actually used and, consequently, the efficiency in the use of means. For example, if the CCEs from # 0 to # 3 are the CCEs associated with the physical resources with which the allocation information for the subject mobile station is mapped, the mobile station decides that the PUCCH # 0 associated with the CCE # 0 With the lowest number of CCEs among the CCEs from # 0 to # 3, be the PUCCH for that mobile station. That is, three different PUCCHs from # 1 to # 3 different from the PUCCH are not used and wasted for the object mobile station.

Therefore, for example, if the search spaces defined in Figure 11 of embodiment 4 are defined, with respect to a plurality of CCEs that form the PDCCH belonging to each search space, a mobile station associates a PUCCH with the number of CCE corresponding to the size of aggregation of CCEs. For example, a PUCCH is associated with eight CCEs with respect to a plurality of CCEs that form a PDCCH of an aggregate size of CCEs equal to 8, and a PUCCH is associated with four CCEs with respect to a plurality of CCEs that form a PDCCH of a CCE aggregation size equal to 4. That is, a PUCCH is associated with n CCEs with respect to a plurality of CCEs that form a PDCCH of a CCE aggregation size equal to n.

However, as described in embodiment 4, if the value of the CFI varies by each sub-frame, the search space range corresponding to each size of CCE aggregation is shifted. By this means, the CCEs that form the PDCCH of each size of CCE aggregation are based on the value of the CFI, and therefore the PUCCHs associated with the CCEs that form the PDCCH of each size of CCEs aggregation go. That is, if the value of the CFI is in vain, the association between CCEs and PUCCHs is not optimal.

In addition, if the association between CCEs and PUCCH resources is notified by a base station to a mobile station each time the value of the CFI changes, the overhead due to notification information increases.

Therefore, based on the association between CCEs in which downlink assignment information and specific PUCCH resources are included to which a response signal is assigned to the downlink data, in which the association is based on of the value of the CFI, the present embodiment controls the sequences of block expansion codes and the cyclic displacement values of the ZAC sequences for that response signal.

Among a plurality of PUCCHs, decision section 210 of mobile station 200 (of Figure 2) according to the present embodiment selects a specific PUCCH to which a response signal is assigned to the downlink data, based on the CCEs that are occupied by the PDCCHs assigned to a specific search space corresponding to the aggregate size of CCEs of the PDCCH to which the allocation information for that mobile station is assigned, from among a plurality of search spaces that go depending on the value of the CFI as in the embodiment 4.

Control section 211 controls the sequences of block expansion codes and the cyclic shift values of the ZAC sequences for a response signal, based on the association between the specific PUCCH selected in decision section 210, the value of displacement of the ZAC sequence and the sequence of block expansion codes, in which the association varies according to the value of the CFI.

This will be explained in detail. The present embodiment uses the same search spaces as in Figure 11 (cFi = 3), Figure 12 (CFI = 2) and Figure 13 (CFI = 3) in embodiment 4. In addition, as in In embodiment 4, the base station 100 transmits search space information (nccE4 (3) = 8, nccE2 (3) = 16, nccE1 (3) = 22) to the mobile station 200.

Among a plurality of PUCCHs, control section 211 reserves a PUCCH resource associated with the lowest number of CCEs occupied by a PDCCH of the smallest size of CCE aggregation.

First, the case of the CFI = 3 will be explained. Among the CCEs from # 0 to # 31 (CFI = 3) shown in Figure 11, in the CCEs from # 0 to # 7 immediately prior to location initial nccE4 (3) = 8 (CCE # 8) of the search space corresponding to the case of a CCE aggregation size equal to 4, a PUCCH resource is associated with CCE # 0 with the lowest number of CCEs among the CCEs that they form the PDCCHs.

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Then, as shown in Figure 11, in the CCEs from # 8 to # 15 between the initial location nccE4 (3) = 8 (CCE # 8) of the search space corresponding to the case of an equal size of CCEs aggregation a 4 and the initial location nccE2 (3) = 16 (CCE # 16) of the search space corresponding to the case of a CCE aggregation size equal to 2, two PUCCH resources are associated with the CCEs with the lowest CCE numbers # 8 and # 12 that form two PDCCHs of a CCE aggregation size equal to 4 which is the smallest CCE aggregation size.

Similarly, as shown in Figure 11, in CCEs from # 16 to # 21 between the initial location nCCE2 (3) = 16 (CCE # 16) of the search space corresponding to the case of an aggregate size of CCEs equal to 2 and the initial location nCCE1 (3) = 22 (CCE # 22) of the search space corresponding to the case of an aggregate size of CCEs equal to 1, three PUCCH resources are associated with the CCEs with smaller numbers of CCEs # 16, # 18 and # 20 that form three PDCCHs of an aggregate size of CCEs equal to 2 which is the smallest size of aggregation of CCEs.

Similarly, as shown in Figure 11, in CCEs from # 22 to # 31 greater than the initial location nCCE1 (3) = 22 (CCE # 22) of the search space corresponding to the case of an aggregation size of CCEs equal to 1, ten PUCCH resources are associated with CCEs from # 22 to # 31 that form ten PDCCHs of an aggregate size of CCEs equal to 1.

That is, in the field below the initial location nCCE4 (i) of the field corresponding to the CCEs of the CFI = i, a PuCCH resource is associated with eight CCEs. Also, in the field equal to or above the initial location nCCE4 (i) and below the initial location nCCE2 (i), a PUCCH resource is associated with four CCEs. Similarly, in the field equal to or above the initial location nCCE2 (i) and below the initial location nCCE1 (i), a PUCCH resource is associated with two CCEs. Also, in the field above the initial location nCCE1 (i), a PUCCH resource is associated with a CCE.

Thus, based on the search space information transmitted by the base station 100, the control section 211 controls the PUCCH resources for a response signal according to the association between CCEs and PUCCH resources, in which the vain association based on the value of the CFI.

At this point, as shown in Figure 14, it is assumed that the order of priority with respect to a use of physical resources associated with PUCCHs (that is, the order of use of sequence numbers) is notified in advance by a base station to a mobile station. At this point, a physical resource (i.e., PUCCH resource) with the least number of PUCCH is preferably associated with a CCE. In the association shown in Figure 14, the PUCCH numbers are defined by the cyclic shift values (0 to 11) of the ZAC sequences and the sequence numbers (0 to 2) of the expansion code sequences in blocks In this case, the PUCCH resources associated with the CCEs are as shown in Figure 15. To be more specific, as shown in Figure 15, the number of PUCCH associated with CCE # 0 is defined by the sequence ZAC # 0 and the sequence of expansion codes in blocks # 0, and the number of PUCCH associated with the CCE # 8 is defined by the sequence ZAC # 0 and the sequence of expansion codes in blocks # 2. In addition, the present invention is not limited to these sequence lengths.

Next, the association between CCEs and PUCCH resources in the CFI = 2 will be explained.

In the same way as in the CFI = 3, the control section 211 associates a PUCCH resource and the CCE with a smaller number occupied by the PDCCH with a smaller size of aggregation of CCEs in the search space of the CFI = 2 among a plurality of PUCCHs.

That is, in the case of the CFI = 2, as shown in Figure 12, PUCCH resources are associated with the CCEs with the smaller numbers of CCE # 0 and # 4 that form the PDCCHs of an equal CCE aggregation size 4 of the CCEs from # 0 to # 7, PUCCH resources are associated with the CCEs with the smallest numbers of CCE # 8, # 10 and # 12 that form the PDCCHs of a CCE aggregation size equal to 2 of between the CCEs from # 8 to # 13, and PUCCH resources are associated with the CCEs from # 14 to # 23 that form the PDCCHs of an aggregate size of CCEs equal to 1 from the CCEs from # 14 to # 23.

In this case, the PUCCH resources associated with CCE numbers are as shown in Figure 16. At this point, comparing the associated PUCCH resources in the CFI = 3 (in Figure 15) and the PUCCH resources associated in the CFI = 2 (of Figure 16), the resources of PUCCH associated in the CFI = 2 shown in Figure 16 are reduced. In addition, the associated CCE numbers are different between the PUCCH resources shown in Figure 15 and the PUCCH resources shown in Figure 16.

Thus, according to the present embodiment, although the value of the CFI varies, through the use of search space information transmitted by a base station, a mobile station can associate CCEs and PUCCHs based on search spaces that work of the value of the CFI. In addition, although the value of the CFI is in vain, it is possible to prepare sufficient resources for the transmission of response signals, reserving only the

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minimum PUCCH resources.

Furthermore, in the same way as in the case of the CFI = 1, as shown in Figure 17, the control section 211 updates the association between CCEs and PUCCHs.

Thus, according to the present embodiment, based on information of search space (on the initial location of the search space corresponding to each size of CCE aggregation) in the specific value of the CFI, a mobile station can Associate CCEs and PUCCH resources according to the change in the value of the CFI. Therefore, in accordance with the present form of realization, although the value of the CFI varies, through the optimal association of CCEs and PUCCH resources in accordance with the definition of search spaces that are based on the CFI and the reservation of only The minimum PUCCH resources, it is possible to prepare sufficient resources for the transmission of response signals without notifying, by a base station to the mobile stations, the association between CCEs and PUCCH resources every time the value of the CFI varies.

Furthermore, although with the present embodiment described above, a case has been described in which PUCCH resources are defined based on the association between the ZAC sequences and the block expansion code sequences shown in Figure 15, Figure 16 and Figure 17, the present invention is not limited to the association between the ZAC sequences and the block expansion code sequences shown in Figure 15, Figure 16 and Figure 17.

In addition, it is possible to use as resources of PUCCH resources other than the cyclic shift values of ZAC sequences and block expansion code sequences. For example, resources that are separated by frequencies such as subcarriers and resources that are separated by time such as sC-FDMA symbols are possible.

Previously, embodiments of the present invention have been described.

In addition, the total number of CCEs that can be used for each sub-frame (that is, the total number of CCEs that may be present in a sub-frame) in the previous embodiments varies depending on the system bandwidth , the number of OFDM symbols that can be used as CCEs, and the total number of control signals (for example, ACK / NACK to uplink data) that are not used to notify the results of allocation of link data resources descending / ascending

In addition, a PUCCH used for the explanation of the above embodiments is the channel for transmitting an ACK or NACK, and therefore can be referred to as an "ACK / NACK channel."

In addition, although previously described cases with embodiments in which CCEs and PUCCHs are associated (ie, downlink data response signals), the present invention can obtain the same effect as before by associating CCEs and PHICHs (Physical Tubed ARQ Indicator Channels). In this case, the response signals to the uplink data are assigned to the PHICHs.

Furthermore, even in the case of using the search spaces shown in Figure 18, it is possible to implement the present invention in the same manner as before. Figure 18 shows the grouping of a plurality of mobile stations and the use of search spaces that are used by each group and the search spaces that are used by each size of CCE aggregation. Therefore, even in the case of the distribution of a plurality of CCEs to a plurality of groups of mobile stations and the application of the present invention to each group, it is possible to obtain the same effect as before. Furthermore, even in the case of using the definition of search spaces shown in Figure 19, it is possible to implement the present invention in the same manner as before. As shown in Figure 19, a configuration is used in which the search spaces corresponding to respective CCE aggregation sizes do not overlap. By this means, different search spaces do not overlap, so it is possible to obtain the same effect as before and reduce the resources to be reserved for PUCCH resources.

Furthermore, even in the case of sending different control signal information in response, it is possible to implement the present invention in the same manner as before.

In addition, a mobile station can be called "terminal station", "User Equipment", "MT", "MS" or "STA (station)". In addition, a base station can be called "Node B", "BS" or "AP". Also, a subcarrier can be called "tone." In addition, a CP can be called "GI (Guard Interval)". In addition, a CCE number can be called a "CCE index."

In addition, the error detection procedure is not limited to the CRC check.

In addition, a procedure of converting between the frequency domain and the time domain is not limited to IFFT and FFT.

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In addition, although a case has been described above with the embodiments in which signals are transmitted using OFDM as a downlink transmission scheme and SC-FDMA as an uplink transmission scheme, the present invention is equally applicable to the case in which that different transmission schemes of OFDM and SC-FDMA are used.

Although a case with the above embodiments has been described as an example in which the present invention is implemented with hardware, the present invention can be implemented with software.

In addition, each function block used in the description of each of the above-mentioned embodiments can generally be implemented as an LSI formed by an integrated circuit. These can be individual or partial chips or totally contained in a single chip. In this document the term "LSI" has been adopted, but it can also be called "Integrated circuit", "LSI system", "super LSI", or "ultra LSI" depending on the different degrees of integration.

In addition, the circuit integration procedure is not limited to the LSI, and its implementation is also possible using dedicated circuits or general purpose processors. After the manufacture of the LSI, it is also possible to use an FPGA (matrix of programmable doors per field) or a reconfigurable processor in which the connections and settings of the circuit cells of an LSI can be reconfigured.

In addition, if the technology of integrated circuits ends up replacing LSI technology as a result of the advancement of semiconductor technology or other derived technology, it is of course also possible to carry out the integration of function blocks using this technology. The application of biotechnology is also possible.

The disclosure refers to Japanese patent application No.2007-280921, filed on October 29, 2007.

According to a first aspect, a mobile radio communication station apparatus is proposed comprising: a reception section that receives a first control channel that occupies one or a plurality of control channel elements and that is assigned to a field of specific control channel element corresponding to a number of control channel elements occupied by the first control channel, from among a plurality of control channel element fields that are dependent on a control format indicator value ; a decision section that decides a second specific control channel to which a downlink data response signal is assigned from a plurality of second control channels, based on the control channel element occupied by the first control channel ; and a control section that controls an expansion sequence for the response signal, according to an association that associates the control channel element occupied by the first control channel and an expansion sequence of the second specific control channel and which varies in function of the control format indicator value.

According to a second aspect, a response signal expansion sequence control procedure is suggested in a second specific control channel to which a downlink data response signal is assigned, the method comprising controlling an expansion sequence. for the response signal, according to an association that associates an expansion sequence of the second specific control channel between a plurality of second control channels and a control channel element occupied by a first control channel assigned to an element field of specific control channel corresponding to a number of control channel elements occupied by the first control channel from among a plurality of control channel element fields that are dependent on a control format indicator value, in which the first control channel occupies one or a plurality of control channel elements and the association varies according to the indicated value control format

Industrial Applicability

The present invention is applicable to, for example, mobile communication systems.

Claims (5)

5 10 fifteen twenty 25 30 35 40 Four. Five 1. A terminal apparatus comprising: a decoding section (209) configured to decode a downlink control channel, which is transmitted in one or more control channel elements, CCEs, which have consecutive CCE numbers from a base station, in a search space that it is composed of a plurality of CCEs that corresponds to a plurality of candidate downlink control channels intended for decoding; and a transmission section (220) configured to transmit a response signal to the base station on an uplink control channel, an index of which is associated with a CCE number of one or more CCEs, in which it is transmitted the downlink control channel, characterized in that: The decoding section is configured to decode the downlink control channel in a search space in which the search space for each aggregation size corresponds to a number of one or more CCEs, in which the channel is transmitted. downlink control, and is defined by a number of the plurality of CCEs and an initial CCE number of the search space, the number of the plurality of CCEs and the initial CCE number being specific for the size of aggregation. 2. The terminal apparatus according to claim 1, further comprising: a reception section (202) configured to receive the downlink control channel, which is transmitted in said one or more CCEs from the base station. 3. The terminal apparatus according to claim 1 or 2, further comprising: an expansion section (219) configured to expand the response signal with a sequence determined from the uplink control channel index, in which said transmission section transmits the expanded response signal. 4. The terminal apparatus according to any one of claims 1 to 3, wherein the total number of CCEs is a function of a system bandwidth, a number of symbols used for the control channels and a number of ACK channels / NACK for uplink data. 5. A method for transmitting a response signal in a terminal, comprising: decode a downlink control channel, which is transmitted on one or more control channel elements, CCEs, which have consecutive CCE numbers from a base station, in a search space that is composed of a corresponding plurality of CCEs to a plurality of downstream control channels candidates for decoding; Y transmitting the response signal to the base station in an uplink control channel, an index of which is associated with a CCE number of one or more CCEs, in which the downlink control channel is transmitted, characterized in that : The search space for each aggregation size in which the decoding is performed corresponds to a number of the one or more CCEs, in which the downlink control channel is transmitted, and is defined by a number of the plurality of CCEs and an initial CCE number of the search space, the number of the plurality of CCEs and the initial cCe number being specific for the size of aggregation.